Vertical axis wind turbine

ABSTRACT

A vertical axis wind turbine (VAWT) may be configured to include air or water bearing supports. The VAWT may be configured to float. The VAWT may include a 360° rotor, having a precision machined noncorrosive bearing surface at its perimeter, with a system of wind capturing devices configured to collect kinetic energy of wind. The rotor may be supported by at least three air or water bearing supports positioned substantially at a perimeter of the rotor. Electrical generation components may be located substantially at the perimeter of the rotor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/544,625, filed on Jul. 9, 2012, now U.S. Pat. No. 8,943,688, which isa continuation of U.S. patent application Ser. No. 12/621,191, filedNov. 18, 2009, now U.S. Pat. No. 8,217,526, which claims the benefit ofU.S. Provisional Patent Application No. 61/115,602, filed on Nov. 18,2008 and U.S. Provisional Patent Application No. 61/158,148, filed Mar.6, 2009, all of which are incorporated by reference as if fully setforth herein.

FIELD OF INVENTION

This invention relates to a gearless vertical axis wind turbine withbearing support and power generation at its perimeter.

BACKGROUND

Power companies need smooth, dependable power. Their experience isalmost entirely with fossil fuel, hydroelectric and nuclear energysources which have very predictable outputs of electricity. As thepercentage of electricity generated by wind power increases so will theamount of variability that they need to account for. The necessaryspinning reserve turbines, which can be fired up quickly when the winddies, represent an inefficiency and direct cost that reduces themarginal value of wind energy. Many resources are currently being spenttrying to develop storage technologies which would enable spreading thepower more evenly across time. So far, only compressed air storage andpumped hydro-storage have the capacity to practically time shift windenergy. Unfortunately, these means are very inconvenient to implementand inefficient.

Wind turbines employ two basic principles to capture energy from movingair. Aerodynamic turbines use low pressure lift; impulse turbines usedrag. The differentiating factor between the two is the blade tip speed.For aerodynamic turbines, the blade tip speed is a multiple of the windspeed. In contrast, an impulse turbine can never spin faster than thewind speed. An anemometer, an often used device for measuring windspeed, is an example of an impulse type device. Conventional horizontalaxis wind turbines (HAWTs) are an example of aerodynamic turbines withtip speeds reaching 100 meters per second (m/s) or 400 miles per hour.

Recent engineering and technical development in modern HAWTs haveresulted in driving their efficiencies to around 35%. The theoreticalmaximum efficiency is limited by “Betts law” to 59%. A wind turbinecannot be 100% efficient as this would imply that the air exiting theturbine would have zero velocity and so would prevent other air fromflowing through the turbine.

Efficiency factors are also misleading in that they presume a certainwind speed which is usually not accurate. For instance a HAWT may have a30% efficiency for the wind speed of 14 m/s, but will not even spin,meaning it would have zero efficiency with a 5 m/s wind. This would bean example of what appears to be logical optimization of the windturbine specifications. The energy in wind is a cubed function of itsvelocity and so optimizing wind turbine efficiencies for high wind speedresults in large megawatt ratings. This is also the number that is usedto describe how big a wind farm is, as in it is a 200 or a 400 Megawatt(MW) wind farm.

According to the National Renewable Energy Laboratory (NREL) windresource map of the continental United States, the best wind resourcesappear to be class 3 and 4 winds over the Rocky Mountain and GreatPlains states. Class 3 and 4 winds represent a yearly average of 6.7 m/sand 7.25 m/s respectively at 50 m above ground. If the average windspeed is 7 m/s, wind speeds of 14 m/s are not likely to happen even aquarter of the time, once factoring in the capacity factors. Capacityfactors are based on the power curve for the particular wind turbine andwind speed data from the proposed site that the turbine will be placedon and are typically claimed to be 25 to 30%. The current paradigm ofHAWTs are designed to have their highest efficiencies in the higher windspeed ranges, which makes sense in the context of the velocity cubedsection of the wind power equation. The goal is to be most efficientwhen there is the most energy to harvest. This results in high MWratings for the turbines but results in low capacity factors, meaningthat the turbine will generate its rated capacity only a small fractionof the time. This results in “peaky power”, that is, most of the poweris made over a relatively short period of time.

The high tip speeds of HAWTs mentioned above create another disadvantagefor the large, conventional aerodynamic turbines. A 100 m swept area hasa 314 m circumference and at 20 revolutions per minute (rpm), the tipstravel 104 m/s. This is a fundamental limitation on the scalability ofHAWT. The tip speed for larger swept areas is limited by the speed ofsound and the specific strength of the blade material to withstand thecentrifugal forces. This speed presents a fundamental risk for birds andfrom fatigue forces over time causing catastrophic blade failure. In theaerodynamic design, the blades are a relatively small percentage of theswept area, making it inviting for birds to try to fly through. Theblade design is also the main reason that the aerodynamic design needs arelatively high wind speed just to start to spin. Combined with thefriction from the gearbox and bearing systems, HAWTs are not effectivein low wind speeds.

Wind speed is seldom constant and since the tip speed of a conventionalHAWT is a multiple of the wind speed, there is significant variation inthe speed of the rotor. This causes huge “on again—off again” loads thatstress the longevity of gear boxes. Additionally, the speed change is onthe wrong end of the gear box, which then increases the speed of therotor 100 times. Consequently, a small change in the speed of the rotorwill result in a large change in the speed at the generator. Thesefactors combine to make the frequency of current generated highlyvariable and erratic. As a result, this requires expensive electricityto condition the grid. In most cases alternate current (AC) asynchronousgenerator current is rectified to direct current (DC). Then, the DC isinverted back to AC three-phase 60 Hz digitally (as a sine wave inlittle steps). There are capital costs, efficiency losses, coolingsystems, power quality problems and maintenance issues that must beborne with this method.

When the focus of the industry changes from the MW rating of the turbineto useful load matching, there will be more interest in turbinesoptimized for average wind speeds. Vertical axis wind turbines (VAWTs)in an impulse configuration have a relatively high efficiency in lowerwind speeds because of their higher blade areas and percentage of sweptarea. Although not as efficient, this design will make power most of thetime the wind is blowing. This is more desirable for power companies andmitigates the need for time shifting or storing wind generatedelectricity.

The capital costs and the reliability of the gearboxes needed to step upthe speed of the main shaft to a speed which is useful for generatingelectricity are other factors in wind power generation. The gearboxcontains hundreds of precision parts. The quality of the bearings, theprofiles of the gear teeth, the stiffness of the gearbox casing and manyother issues make gearbox manufacturing a precision engineering art.Precision machine tools and skilled labor are required to construct thecomponents for these gearboxes. Considering gearboxes account forapproximately 30% of the cost of the new turbine, gearbox availabilityhas been a limiting factor in the supply chain for wind turbines. Oncein service, a failure of any single part is likely to result in thefailure of the entire gearbox. The risk of new, larger machines andunproven gearbox designs will be an impediment to reaching offshorewinds. Installation and maintenance costs of offshore turbines are threetimes the cost of land-based turbines, which has prevented the EastCoast from having a single offshore wind turbine. The present inventionwould eliminate the costs associated with the gearbox and additionallyresult in shorter manufacture times for turbines.

The broad support base and low center of gravity in the VAWTconveniently enables flotation of the turbine. Trying to float a HAWT iscomparatively much more difficult, because a mass fixed high on a heavypole is fundamentally unstable. Flotation is a key design aspect of thepresent invention. Research by the NREL has confirmed the huge potentialadvantages of floating wind turbines, including estimates of over 1000GW of estimated power in offshore wind resources surrounding thecontinental United States.

As mentioned above, the energy in the wind increases as the cubefunction of its velocity, so class 6 winds have more than double theenergy of class 4 winds. Also the wind velocity near the surface is muchhigher and this reduces the need to elevate the turbine into the air.These two factors, along with a multitude of other advantages,effectively counteract the relative inefficiency of the vertical axiswind turbine.

Power transmission is also a problem associated with making wind power aviable energy solution. As noted before, the best winds on thecontinental United States are class 3 and 4 winds in the Great Plainsand Mountain states which are 1500 miles from major load centers.However, there are class 6 winds just 30 miles offshore. Over 75% of theelectricity consumed is along the coasts and Great Lakes which arenearly the best wind resources available to the United States. Underseacables are much less expensive to permit and do not require high tensiontowers. And clearly, the 30 to 50 mile offshore range is significantlyshorter than the 1500 mile run currently contemplated and needed totransmit power to and from the East Coast. Such shorter distances resultin reduced costs and transmission losses. In fact, undersea cables havea very significant advantage in that they are insulated from summertimeheat. Higher temperatures reduce the conductivity of transmissioncables, so when the grid is most strained, during the summer heat, thatheat reduces the transmission capacity. Alternatively, undersea cablesare not subject to this loss, which is amplified by the longer length oflandlines.

Power plants are often located near the coasts or Great Lakes for accessto coal and cooling water. Many of these power plants have beendecommissioned or are only used for peak load because of oldturbine/generator technology. However, their connection to the gridstill exists. They were intentionally located near the high demandcenters and offer the ultimate in “smart grid recycling”, providingready-made high amperage distribution points for offshore wind power.

An additional advantage of VAWTs over HAWTs involves wind direction andmaximizing power generation. VAWTs are not sensitive to wind directionand do not require being pointed into the wind. In contrast, HAWTs needto be pointed into the wind, and so far, there has been no reasonableplan to deal with this issue except for huge, economically impracticalfloats. The proposed 3-point floatation provides convenient places forthree mooring tethers to provide the required anti-rotation. The VAWTwill always wind up and tighten its tethers in the same direction, whilethe HAWT needs to be actively pointed into the wind. Accordingly, thereis a need to provide VAWT capable of generating power offshore.

The floating VAWT would address many of the technology and policyproblems of a marine-based HAWT. Because the turbines solve theflotation problem, no foundation is required on the sea floor. This is ahuge reduction in marine citing costs, making them cheaper to site thanland-based turbines. The VAWT would be built on shore, towed out to afield of mooring anchors, tied up and plugged in. No crane or assemblywould be required at sea, again resulting in an order of magnitudecost-reduction.

Recent policy decisions by high-ranking government officials indicatethat offshore wind energy is becoming a top priority. The proposedinvention for floating offshore wind turbines is not just consistentwith, but enables, the new national policy direction by eliminatingpolicy, cost and technical roadblocks as mentioned above.

Because the wind farms for the VAWTs would be located in deep waterwhich have been off-limits to HAWT, there is not an either-or choicebetween the turbine technologies. VAWTs may be seen as an additionallayer of wind energy capacity that can be built on top of the alreadyexisting wind turbine manufacturing industry. Due to the higher qualitywinds and lower costs associated with VAWTs, there is a need for thisturbine technology.

SUMMARY

A vertical axis wind turbine comprising a 360° rotor with an aerodynamicor impulse based system of blades or deployable sails attached to it forcollecting the kinetic energy of the wind, the rotor being supported ona three-point independent fluidic or magnetic bearing support points. Avertical axis wind turbine comprising; a three-point bearing supportbearing employing fluidic or magnetic bearing technology to support arotor of 360° which has an aerodynamic or impulse based systems ofblades or deployable sails attached to it for collecting the kineticenergy of a wind. A wind turbine with permanent magnets arrayed aroundthe inside perimeter of the rotor with segments of coils arranged inclose proximity to the magnets at each of the bearing points for thepurpose of generating electricity. A wind turbine with coils arrayedaround the inside perimeter of the rotor which are connected via slipring to a variable current for the purpose of varying the resistance andthe amount of electricity generated for a given rpm. This makes itpossible to have a constant rpm machine and so provide 60 hz 3 phasepower directly, without conversion from AC to DC and back to AC.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a proposed VAWT.

FIG. 2 is a perspective view of a concrete footer.

FIG. 3 is an above-perspective view of a proposed VAWT.

FIG. 4 is another perspective view of a concrete footer.

FIG. 5 is a side view of an offshore VAWT.

FIG. 6 is a side view of another offshore VAWT.

FIG. 7 is a schematic view of a network of offshore wind turbines andtheir respective mooring system.

FIG. 8 is a flow diagram of a method of manufacturing large steelrotors.

FIG. 9 is another perspective view of a proposed VAWT.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Bearing technology with the capacity and speed to support a large sweptarea at the perimeter of a vertical axis wind turbine (VAWT) hasrecently become commercially available. Hydro turbines and steamturbines both use hydro bearings to support their rotors. Governmentgrants are currently being solicited for request for proposals relatedto bearing systems and wind turbines.

When referred to hereafter, the terminology “bearing” may include amagnetic bearing, air bearing, hydro bearing or any other fluidicbearing. When referred to hereafter, the terminology A wind capturingdevice may include a blade, deployable sail, vain, or air foil.

A VAWT as shown in FIGS. 1-4 may be manufactured with the followingtechniques. The novel three-point stance is accomplished by firstproviding at least three concrete footers 100 or small foundations towhich the bearings 150 will be attached. The concrete footers arearrayed 120° apart from each other and approximately under the perimeterof the turbine, thus creating an equilateral triangle. This is akinematic support method which avoids the problems of a 360° baseneeding to be precision fit to the 360° rotor. By eliminating the baseand using a three-point support, the bearings will always be presentedparallel to the rotor bearing face and in a plane no matter how muchdistortion there is in the rotor or the position of the three-pointfooters.

The concrete footers 100 may project from the earth a typical 1 to 3 m.Because the corners of the triangle are located relatively far apartfrom each other, as compared to a single point stance of conventionalHAWTs, the moment forces that are exerted on the upper sections of theturbine are spread across a much wider support scheme at the base.Depending on the total weight of the rotor and aerodynamic structure, itmay be necessary to have a third bearing race on top of the rotor tohold down the windward side of the rotor in heavy winds. Because of thebroad support, the total amount of concrete required is dramaticallyreduced. Large steel pins 201 are cast into the concrete footers whichprovide the connection between the footers and the bearing elements asseen in FIG. 2.

For very large turbines, where it may be necessary to support hundredsof tons, bearings may be ganged together in a wiffle-tree fashion. Thistechnique is common practice for locomotive and cargo crane wheels as amethod for being sure that multiple wheels or in this case bearings seean even distribution of load at all times. If 7 spherical pivots areused, 4 bearings may be mounted; if 3 pivots are used, 2 bearings may bemounted. Even when using a single bearing, it should be free to pivot tobecome parallel with the rotor.

Another feature of this embodiment is the ability to transport andprecision machine a massive rotor 910 as shown in FIG. 9. A method formanufacturing large rotors for VAWTs and flywheel energy storage withfluidic or magnetic bearing races can be achieved through the followingmethod. Pre-rolled or bent steel is welded together to comprise therotor. The completed rotor will be supported by, but not in contactwith, at least three points, evenly spaced around the circumference asdescribed above. There is also a center abutment 930 that is fitted witha large spindle 940. The spindle may be a rolling element, planebearing, hydrostatic or air bearing spindle for example. This spindle isused as a crane to position the steel segments around the perimeter. Thespindle also provides a way to measure the position of the steelelements before welding. The steel segments are welded together. Thecenter spindle is designed so that using multiple arms 950, it maysupport the entire steel rotor. The center spindle is fitted with amotor for driving the rotor. One of the perimeter pedestals 920 is fitwith modular machine tool slides. Spindles and tools may be mounted tothe slides in order to precision machine the rotor in-place. After themachining operation, these slides, or another set of slides, are fitwith a flame spray apparatus. The flame spray apparatus is used todeposit a coating of nickel, or other appropriate noncorrosive material,onto the prepared and machined bearing surfaces on the rotor. Thiscoating is built up to be more than a millimeter thick. The flamesprayed nickel is then precision machined or ground. In this way anoncorrosive bearing surface with the appropriate precision can becreated in the field. This avoids the problems associated with having totransport such a large rotor. Such rotors can be used as flywheels andenergy storage devices or as rotating bases for vertical wind turbines.In order to reach the highest possible rotational speeds, it may benecessary to use continuous carbon fiber windings around the outsideperimeter of the rotor. Fluidic or magnetic bearings are then used tokinematically support the rotor while it is spinning as a wind turbineor energy storage device.

The aerodynamic or impulse scheme for collecting the energy from thewind is constructed on top of the rotor which is supported on the nearfrictionless fluidic or magnetic bearings. A scheme for collecting theenergy from the wind should be light-weight. Multiple (at least three)posts such as sailboat masts are arrayed vertically with their baseattached to the lower rotor described above. It is common practice insailboat construction to have a mast supported by stays (wires) whichattach at the bow and stern of the ship to provide forward and backwardstability to the mast. Side to side stability is also provided by stayswhich mount in the deck to port and starboard of the mast. These staysare under tension and work against the column stiffness of the mast. Inthis way, a 7-to-1 ratio between the height of the mast and the distancebetween the port and starboard stays on the deck can easily be achieved.By connecting the tops of the masts together, either with a singlemonolithic piece of fiberglass (which can also be fabricated on siteusing conventional techniques) or by modular pieces linking the top ofeach mast, a cylindrical shape may be created. By further employingstays which connect this top structure and/or the tops of the masts tothe lower rotor on chords of the cylinder, in a similar fashion tobicycle spokes, produces a very stiff yet lightweight cylindrical shape.In summary, a structure which is stiff, regarding both bending andtorsion, may be constructed by using wires in tension, columns/masts incompression and the hoop stiffness of the lower and upper rotors.

A proposed VAWT may run at an exact speed to have the rotor coils andstator poles generate three-phase, 60 Hz power directly for the grid.Additionally, limited power conditioning equipment is required. First, agenerator will be located on the perimeter of the rotor, so it has thehigh surface-speed required to produce 60 Hz. Because it does not have a100-to-1 generator between it and the rotor, it experiences much lessspeed variability. Second, the speed variability could be reduced moreby placing the mass of the lower rotating ring intentionally high toincrease its inertia and dampen the effects of changing wind speed.Alternatively, it is possible to servo the magnetic field in the rotorcoils to maintain a constant rotation speed. As a result, when the windblows harder, the control system increases resistance in the magneticfield, keeping the rotation speed constant but the electrical currentoutput increases. This would be an effective way to eliminate the costand problems associated with power conversion equipment. However, thistechnique would not be as economical to produce and potentially wouldnot be as efficient as a permanent magnet machine.

The framework described above provides an excellent support structurefor multiple types of systems for wind power generation. Wind capturingdevices, such as fiberglass blades 101 shown in FIG. 1 are supported onboth ends and can be made lighter than the cantilevered blades on HAWTsthat are only half their length. Alternatively, the wind capturingdevices may be deployable sails, such as roller furling devices. Thesedeployable sails may be activated by wind pressure as they come to thewindward side of the turbine, could release a significant sail area thatwould be very effective at catching the wind on the downwind side of theturbine and roll up at the leeward side to dramatically reduce theirresistance on one side of the turbine. Such a system would dramaticallyincrease the efficiency of the VAWT without adding unreasonablecomplication. Also the ability to furl all of the sails in stormconditions dramatically reduces the windage exposure of the turbine.There are many other options for the system, as such, these examples arenot meant to limit wind generation possibilities.

Alternatively, the wind capturing devices may be rigid blades, each withits leading edge hinged, like a vane. In this configuration, it willmitigate its windage on its up wind trip like a directional wind vane ora flag and then flip out to catch a maximum amount of wind on thedownwind side of the turbine.

In another embodiment, the electrical generation section of the machineis direct drive generation at the perimeter, eliminating all driveshafts, gearboxes and conventional generators. A possible embodimentincludes the case where windings are arrayed around the insideperimeter. These windings are connected through conventional brushes tothe control system and energy source. The current to the windings in therotor could be served such that there would be an increase or decreaseto the magnetic drag and hence the power generated. By using this servocontrol to maintain a constant rpm, it would be possible to design thegenerator components to produce 60 Hz three phase power at that speed.Thus, when the wind blows harder, field resistances increase and moreelectricity is produced at the same speed. This would avoid a number ofpower conditioning issues.

Another embodiment employs permanent magnets on the perimeter of therotor. This would be less expensive and possibly more efficient butwould suffer from the need to convert the energy to DC and then back toAC of the rotor machine.

FIG. 5 shows another embodiment in which a method and apparatus aredisclosed for floating a VAWT on a flotation system using at least threeflotation points are provided. By not requiring a 360° base for theturbine the ability to float the turbine is greatly simplified. As canbe seen by observing government navigation marks and buoys, wave actionhas little effect on the horizontal position of these marks. Thiselement can be employed to maintain stability of the above water sectionof the turbine. Hollow float bodies that may be cylindrical ortriangular in profile extend a multiple of their exposed lengths belowthe surface of the water. The connection of these floats to the bearingelements supporting the rotor would be consistent with description forthe land-based turbines above.

In one embodiment these floats also have horizontal fins extendingtowards the center of the axis of rotation. These fins add verticalstability by requiring water to be displaced for the float to movethrough the water vertically. By extending these fins towards the centerof the turbine they will stay clear of the structure used to tie thethree floats together and the mooring tethers which may attach to thelower outside corner or perimeter of the float. These floats may beconstructed of steel, aluminum or fiberglass for example.

In another embodiment, vertical stability of these floats may also beenhanced by allowing the lower section of these floats to fill withwater. The water thus increases the mass of the float and so will act asa mass damper to the above water section of the turbine.

By using three floats, for example, calculations are relatively easy todirect the adjustment of the buoyancy of each float so as to keep therotor of relatively parallel to sea level. This can be accomplished byusing a compressor which is powering the air bearings to pump air intothe top of the floats thus displacing water out the bottom of thefloats. The hole in the bottom of the float is sized so as to maintainthe damping effect with respect to relatively short-term wave action,but still allow for adjustments regarding longer-term changes in averagewind speed over the period of several minutes.

The floats may also be equipped with internal compressed air cylinders.In the unusual event of a large hurricane class storm, air in the floatsmay be vented to atmosphere by a remotely controlled valve allowing theturbine to sink to the ocean floor and remain entirely below sea leveluntil the storm has passed. When the storm has passed a remotecontrolled valve allows compressed air in the cylinders to again fillthe float and raise the turbine to the surface. Because this turbinedesign does not contain a gearbox there may be little or no oil on boardthe turbine. The air compressor may require replacement as would safetylighting that would be required for the turbine and possibly some otherminor components. However, the bearings and the generators would not bematerially harmed by being submerged. This method of scuttling theturbine solves one of the major risk factors for offshore wind powergeneration.

FIG. 6 shows another embodiment in which a method and apparatus forfloating the VAWT are provided. The vertical axis wind turbine may besupported on a 360° floating hull 104 made of steel, aluminum orfiberglass, for example. It is recognized that there would besignificant viscous sheer drag between the hull 104 and water, but thesimplicity of this embodiment is compelling, requiring no weightcarrying bearings for the turbine. The stator section of the generatorcomponent would be relatively light weight. In this embodiment the threemooring tethers would connect to this stator. The connection to therotating and floating section of the turbine could be through rollerssuch as truck tires, for example. A ship 105 is also shown in FIG. 6.

There are multiple methods which may be employed in order to reduce theviscous drag of the hull in the water; Air bubbles could be releasedfrom the lowest section of the hull. Surface texture tricks which havebeen employed on sail boat hulls. Foils 610 may be deployed under thehull 104 that through a hydrodynamic action would lift the hull out ofthe water. This technique has been employed on military ships, furryships catamaran sail boats and even the sailboat one design moth class.

It should be noted that in most normal cases, such a floating windturbine would have a cable attached to it for the purpose oftransmitting power that is generated by the turbine. It should befurther noted that there may also be a cable carrying electrical powerto the turbine for the purpose of safety lighting, providing energy forthe air compressor or magnetic bearings and or providing conduit forcommunications, control and monitoring of the turbine functions.

FIG. 7 is a schematic view of a proposed network of offshore windturbines and a proposed mooring system. The mooring system designincludes a plurality of anchor points on a sea floor. Each of theplurality of anchor points are configured to anchor at least threevertical axis wind turbines (VAWTs) to the sea floor. Therefore, eachanchor point is configured to secure at least one tether 303 from upthree VAWTs.

FIG. 8 shows a method 800 of manufacturing large steel rotors used withfluidic and magnetic bearings used in wind turbines and flywheel energystorage devices. The method beings by providing a temporary centerbearing and a spindle, the bearing and spindle capable of supporting andspinning a fabricated rotor, at step 810. Then machining a surfacearound a perimeter of the rotor to produce a machined surface, at step820. Then, flame spraying a noncorrosive material onto the machinedsurface, at step 830. Then re-machining the flame sprayed surface intoan appropriate bearing surface for fluidic and magnetic bearings, atstep 840.

Although features and elements are described above in particularcombinations, each feature or element can be used alone without theother features and elements or in various combinations with or withoutother features and elements.

What is claimed is:
 1. A vertical axis wind turbine (VAWT) comprising:at least three bearing supports; a 360° rotor, having a precisionmachined bearing surface at its perimeter, with a system of windcapturing devices configured to collect kinetic energy of wind, whereinthe rotor is supported substantially at the perimeter by the at leastthree bearing supports wherein the bearing supports are one of magneticbearings, air bearings or fluidic bearings; and electrical generationcomponents that are substantially at the perimeter of the rotor.
 2. TheVAWT of claim 1 wherein the at least three bearing supports are threeair bearing supports configured to kinematically support the rotor.
 3. Abarge configured to generate electricity, the barge comprising: a hullconfigured to float; and a vertical axis wind turbine (VAWT), supportedby the hull, wherein the VAWT is configured to generate electricity at aperimeter of the hull, wherein the VAWT comprises a 360° rotor, having aprecision machined bearing surface at its perimeter, with a system ofwind capturing devices configured to collect kinetic energy of wind,wherein the rotor is supported substantially at the perimeter by atleast three bearing supports.
 4. The barge of claim 3 furthercomprising: at least three tethers configured to connect the barge tothe sea floor.
 5. The barge of claim 3 wherein the hull includes aremotely controlled valve configured to flood the float and sink theturbine below sea level.
 6. The barge of claim 5 wherein the hullincludes a remotely controlled compressed air cylinder, or other sourceof compressed air, configured to fill the float with air and refloat theVAWT.